Heating apparatus



No-Model.)

R. CALDER. A HEATING APPARATUS.

No. 472,940. Patented Apr. 12,1892.

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INVENTOH WITNESSES 2 Q WWMJ 4 ATTORNEYS 1 U ITE STATES PATE T OFFICE.

ROBERT CALDER, CE ROCHESTER, 'AssieuoR TO FRANCIS r. GIBLIN, OF UTICA,NEW YORK.

HEATING APPARATUS.

SPECIFICATION forming part of Letters Patent No. 472,940, dated April12, 1892.

Application filedMay 21, 1891. Serial No. 898,553. (No model.) i

heaters, as hot air and steam or hot air and hot water. My object is toprovide the apparatus with improved means and appliances by which theair is primarily partly heated before it comes 1nto contact with theexterior of the fire-pot and combustion-chamber, which is the hottestradiating-surface.

My apparatus .is provided with two airheating chambers, one below thelevel of the grate and the other above,with a partition between them,which retards and distributes the air and is also perforated, so thatthe air can pass from the lower to the upper chamber, the lower chamberbeing provided with a tubular radiator, through which the products ofcombustion are conducted to the smoke-pipe by the indirect draft.

My invention consists in the several novel features of construction andoperation hereinafter described, and which are specifically set forth inthe claims hereunto annexed.

It is constructed as follows, reference being had to the accompanyingdrawings,in which- Figure 1 is a side perspective view of an hot-airheating apparatus with part of the casing broken out to show theinternal construction. Fig. 2 is a transverse section on a line belowthe partition and parallel with it and above the heat-radiating smokebox. Fig. 3 is a top plan of the partition, which is located between thecasing and fire-pot and substantially below the grate.

A is the body of the furnace, comprising the ash-pit 1, fire-box 2,combustion-chamber 3, and dome 4, shown as subdivided, and having thedivisions connectedby the pipes 5, which. are also connected to thehorizontal pipe 6, the rear end of which is the directdraft pipe leadingto the chimney 7; This pipe 6 extends to the casing in front, and 8 is aremovable closure in its outer end, and its removal enables me to cleanthis pipe from the front.

In the base of the furnace, and resting upon the skeleton bottom 9thereof, I place my primary air-heating annular radiator 10, the top ofwhich is below the grate and which is of such form as to fit around theash-pit and having its front ends adjacent to the sides of said ash-pit,the arrangement of the radiator leaving an inner annular space 1O aroundthe ash-pit and an outer annular space 10 between the casing and theradiator. 11 1-1 are pipes connecting the front ends of this radiator tothe front end of the indirect-draft pipe 6, and at the rear theindirectdraft smoke-pipe 12 connects this radiator 10 to thechimney-pipe 7. At a little distance above this radiator and closing thespace between the casing 13 and the ash-pit on both sides, and havingits front ends fitting closely against the clean-out portion of theash-pit,I place a partition 14:, which is provided with perforations 15of rather small size at its inagainst the wall of the fire-box. Theair-inlet pipe 16 opens into the chamber below the partition 14 anddischarges fresh air directly against the primary radiator 10. Thisprimary radiator is heated by the products of combustion when the directdraft damper (not shown) in the pipe 6 is closed, forcing thev productsof combustion through this pipe and downwardly through the pipe 11 intosaid radiator 10, through which they pass and are conducted by the pipe12 to the chimneypipe. In this manner the air is primarily heated bysaid radiatorlO in this lower chamber and can only escape therefromthrough the perforations 15, so that this plate both operates to retardthe air and hold it in contact with said radiator and at the-same timeto cause its distribution all around this par-' tition-plate and throughall of the perforations, so that when it enters the upper chamber itisdiffused all around the fire-pot and when it encounters the fire-potand the outer wall of thecombustion-chamberand of the dome also, whichconstitute my secondary air heating surface, which is the hottestsurface I utilize the heating-of the, products of combustion to theutmost extent. i

What I claim as my invention, and desire to secure by Letters Patent, is

Thecoinbination, with the ash-pit, the firebox, the combustion-chamber,and the casing,

of the skeleton bottom, the annular radiator seated onthe skeletonbottom, leaving aspace betweenitand the ash-pit and also aspace betweenit'and the casing, the indirect pipes connecting the combustion-chamberwith the radiator, air-inlet pipe discharging against the radiator, andthe partition located a little distance above the radiator, closing thespace between the ash-pit and the casing and having perforations bywhich the air is diffused all around the fire-box, substantially as de-25 scribed.

' In Witness whereof I have hereunto set my hand this 15th day of May,1891.

ROBERT CALDER. In presence of F. T. GIBLIN, Ron'r. W. BRYCE.

